Abstract: A system for a providing a multi-rate digital low pass filter that attenuates high frequency resonances in a control signal. The filter described by a transfer function having a phase-advanced factor (or an approximation of phase-advanced factor) and a low pass filtering function; either cancels or avoids an unstable pole in the phase advanced factor at z=?1.

Abstract: A slider includes a void for controlling the flying height of the slider over a disk in a HDD. The slider comprises a slider body having a leading surface and a trailing surface. A read/write element is formed in a portion of the slider body proximate to the trailing surface of the slider body and a first thermal heater proximate the read/write element, wherein a first void is defined within the slider body proximate to the read/write element for increasing a mobility of the read/write element to increase the protrusion when thermal energy is introduced to the read/write element.

Abstract: This invention relates to a slider that includes a thermal actuator for controlling the flying height of the slider over a disk in a HDD. The thermal actuator comprises a thermal insulator, a thermal heater and a thermal conductor. The thermal heater is proximate a bottom surface of a slider body on one side of a read/write element. The thermal conductor has a higher thermal coefficient of thermal expansion than a remainder of the slider body and is formed between the first thermal heater and the one side of the read/write element. The first thermal insulator is proximate the bottom surface of the slider body and adjacent to the first thermal heater on an opposing side of the first thermal heater.

Abstract: A system for a providing a multi-rate digital low pass filter that attenuates high frequency resonances in a control signal. The filter described by a transfer function having a phase-advanced factor (or an approximation of phase-advanced factor) and a low pass filtering function; either cancels or avoids an unstable pole in the phase advanced factor at z=?1.

Abstract: This invention relates to a system and method performed by a controller in a hard disc drive to generate a write fault signal. The system performs in the following manner. The system begins by receiving a sample of a position error signal. The system then generates a control signal from the position error signal. A sample of the control signal is then captured by the system. The system then determines a parameter to test from the captured sample of the control signal. The absolute value of the parameter is then calculated and compared to a threshold value. The system then generates a write fault error signal in response to a determination that the absolute value of the parameter is greater than or equal to the threshold value.

Abstract: A system for removing low frequency disturbance signals from a control system output. The system includes a controller, a mixer, a feedback loop, and a low pass filter. The controller generates a control signal. The mixer is connected to the controller and receives the control signal from the controller. The feedback loop connects an output of said mixer to an input of the mixer. A low pass filter in the feedback loop allows low frequency disturbance signals in the control signal output from the mixer to pass through the feedback loop and to be added to the control signal by said mixer for handling by the controller.

Abstract: A system for removing low frequency disturbance signals from a control system output. The system includes a controller, a mixer, a feedback loop, and a low pass filter. The controller generates a control signal. The mixer is connected to the controller and receives the control signal from the controller. The feedback loop connects an output of said mixer to an input of the mixer. A low pass filter in the feedback loop allows low frequency disturbance signals in the control signal output from the mixer to pass through the feedback loop and to be added to the control signal by said mixer for handling by the controller.